Company network using time slot reuse

ABSTRACT

An arrangement and a device comprises a mobile data and communication network within a predetermined geographical area. The device operates with first and second functions that can consist of, for example, company and/or customers functions and communication and/or slave functions respectively. Two or more units in the first function are synchronized with each other as regards time and frequency in order to act, from the point of view of connection and disconnection functions, as a common first unit for second units that carry out the second function. Time consuming handshaking procedures are then avoided for the second units when these one&#39;s are moving and shifting between part areas of said predetermined area and the total system will operate rapidly in this respect.

[0001] The present invention relates among other things to acommunication system where the transmission of signals between differentnodes takes place via company nodes (master nodes) that allocatespermission to transmit to the respective mobile customer (slave) nodesin given time slots. The invention also relates to a device in the formof a mobile data and telecommunications network within a predeterminedgeographical area, for example within a company, factory, hospital, etc,and working with first functions, for example in the form of company(master) functions and second functions, for example in the form ofcommunication functions and/or customers (slave) functions, establishedby means of fixed and/or movable nodes and/or mobile units. In addition,the invention relates to an arrangement with a mobile telecommunicationsand/or data network located in a geographical area, which networkcomprises company (master) functions and mobile customer (slave)functions.

[0002] A well-established way of carrying out wireless communication isto set-up a cell with a base station that has a number of transmittingand receiving stations within its area. These communicate with eachother via the base station, that is the transmitting station has an “up”link to the base station and the receiving station has a “down” link. Awell-known system with this construction is Bluetooth. The invention isdescribed using Bluetooth as an example, but can also be implemented inall similar systems.

[0003] Bluetooth allows a master to provide service to up to sevenslaves that are active.

[0004] An unlimited number of slaves can be put in Park Mode and caneither be activated by the master or activate themselves. A master canhave a very restricted range. It is usually a question of a restrictionto approximately 10 m, but technically a considerably larger range canbe achieved. Bluetooth provides standardized profiles that can be usedin the present invention, for example, K1-6 and K9 are relevant.

[0005] It is desirable to be able to use Bluetooth standard units asheadsets, PCs, mobile telephones, etc, in order to provide service fromvarious sources, for example companies, within their geographical area,for example, within a department store, a petrol station, etc. A problemis that there are many customers in the area, and that each node in thecompany's network can only handle at most seven customers at a time.This means that it is necessary to have many masters within the area,and as these utilize the frequency range independent of each other,there is an inefficient utilization of the local bandwidth. In addition,the customers, that is the Bluetooth slaves, must re-synchronize orrather execute handshakings frequently to new masters. Said handshakingprocedures are time consuming in Bluetooth.

[0006] Solution

[0007] The company arranges a Bluetooth network in the usual way andsets itself up as the master in the pico-network. By this means, fullcontrol is obtained of the bandwidth utilization for the slavesconnected to the pico-network. By synchronizing for time and frequencyall the master nodes belonging to the company within the area, these canappear to be one and the same master to all the slaves within the area.

[0008] Design of the Company's System

[0009] The company's nodes differ from the Bluetooth specification inthat they are synchronized to one and the same clock, that is each nodein the company refers to one and the same Bluetooth time. In addition,their frequency hop is synchronized.

[0010] All use the same frequency and change frequencies simultaneously,and they use the same BD_ADDRESS. In this way, the Bluetooth nodesbelonging to the customers that are connected up to the company networkat any time, perceive that they are interacting with one and sameBluetooth master regardless of which company node is within their range.

[0011] At each node in the company system there is a gateway to a commonnetwork for the company that can be cable-based or wireless. In thewireless version, certain time slots in the planning of the nodes'Bluetooth schedule can be reserved for communication between adjacentcompany nodes. Through the common company network, the nodes canexchange messages with each other and/or a central node belonging to thecompany with database and connection to other public networks such asthe Internet, public telephone network, etc.

[0012] The company nodes are preferably permanently installed and theirgeographical location is arranged to suit their antenna layout or viceversa, so that a suitable range pattern and overlap pattern is obtainedbetween them, and the time slots are scheduled so that the availablebandwidth serves an optimal number of customer nodes in the system withregard to quality and availability. As the company nodes aresynchronized with each other, the company network occupies a minimalpart of the available bandwidth. The concept can be developed further sothat the company can have several parallel networks that are coordinatedwith each other so that collisions between them do not occur. In thisway, the maximal space is created for other Bluetooth nodes within thearea.

[0013] Synchronization

[0014] The customer nodes synchronize themselves to the company networkpreferably at special synchronization nodes, but alternatively this canbe carried out at any company node. The synchronization method does notdiffer from the Bluetooth standard. In conjunction with thesynchronization, appropriate information is exchanged for furtherservice provision in the system, for example, name, account number,customer profile, etc, and is updated in the central database. Thecentral unit can be connected to a GPS node and can thereby besynchronized to GPS time, whereby the company's Bluetooth time can besynchronized to GPS time. Customer nodes that are synchronized to GPStime and that have the ability to synchronize their Bluetooth time tothis, can thereby be synchronized to the company's nodes viasoftware/data sent to them without synchronizing themselves via thesynchronization node, or alternatively, after having synchronizedthemselves once in the conventional way, they will thereafter bepermanently synchronized via the GPS time.

[0015] Operation

[0016] As all the company nodes are able to communicate with each otherand with the central node, the active company nodes can be served in asuitable way. The different company nodes are scheduled so that theyhave particular exclusive time slots within their area of coverage.Outside the area of coverage, the same time slots can be allocated toother company nodes. In overlapping areas, a time slot that has beenallocated to a company node can be listened to by the other companynodes. By measuring the signal strength (RSSI), an adjacent node cantake over a customer node from an adjacent company node. There areseveral more or less sophisticated solutions for this. The simplest canbe to take over when the signal strength exceeds a pre-programmedthreshold value. Another can be that during a transitional stage, two(or more) company nodes allocate the customer node a time slot belongingto the respective company node. The information from the customer nodecan be used by the company node that currently requires it, as all canlisten. Sniff, Hold and Park Mode can be used according to the Bluetoothspecification in order to utilize the available bandwidth in the optimalway. Beacon signal, Beacon access windows, etc, can be synchronizedwithin the whole company, and customer nodes can thereby attractattention when the customer needs to access the company system.

[0017] Scenario

[0018] The customer drives within range of a synchronization node in thecompany system. The customer's BT node is synchronized to the companynetwork and the customer is asked what he is interested in. The customerreplies, for example, “shoes”. The company system gives a list of allthe places that sell shoes within the system and what type of shoes. Thecustomer selects one of the suggestions and the company system informshim of the nearest available parking place. The customer can be directedto this either via his own navigation system using GPS coordinates, orby the respective company nodes on the way giving appropriatedirections. Once he is parked, the nearest company node sends theinformation about the car's parking place to the central node, whichstores it in memory. The customer now leaves the car and the car's BTnode provides the requisite information to the driver and passengers' BTnodes and information about which these are to the company system. Thedriver and passenger nodes connect to the company system. Theinformation is saved in the central system. As the customers move aroundin the company system, this is updated and one company node is activewhile adjacent nodes monitor the communication and are ready to takeover the respective node. The customer nodes can be directed to go intoPark Mode by the company system when this is appropriate. The customernodes can themselves also request to be directed into Park Mode. PM_ADDRcan be used and in this way the company can wake up the nodes at regularintervals. Several customer nodes will have the same PM_ADDR, but as inmost cases they will be in contact with different company nodes, theywill not collide. With a PM_ADDR, the company system obtains informationabout where a plurality of customer nodes are to be found in the system.BD_ADDR can always be used if there is a need to wake a particularcustomer node. The company system can choose which company nodes are tosend the command. This can be one, several or all of them. If severalgive the command, this preferably takes place simultaneously. Withknowledge of the most recent customer position, suitably located companynodes can be used for the purpose.

[0019] Our family has now arrived at the shoe shop. This is the locationof a number of company nodes. These can in turn be connected, via radio,infrared or cables, to one or more shoe-shop nodes that correspondlocally to the central node. These local central nodes are connected tothe company system. The local node suitably covers a geographical areasuch that it can serve up to six or seven customers. The customer sees ashoe he is interested in and reads its identity. (In a furtherdevelopment of the concept, the information can be scanned in, enteredvia an electronic tag, etc.) He asks the system whether it is availablein size 45. The system checks whether such is the case and informs himof the result. If the shoes are available, the system asks the customerif he wants to try on a pair. If he replies in the affirmative, thesystem informs the nearest assistant (who is also connected to thecompany system) of the request and where the customer is located. Thecustomer tries on the shoes and likes them. The customer informs thesystem that he wants to buy the pair. The system informs him of theprice and which account is to be charged and asks the customer for aconfirmation. The customer gives a confirmation and the company systemimplements the transaction. If the shoes have an anti-theft device, thisis deactivated in an appropriate way. The customer takes the shoes andleaves.

[0020] Now the husband and wife have been separated for a short while.The husband asks the system where his wife, or more precisely where hiswife's customer node, is located. The system checks via the central nodewhere she most recently made contact. If her node is active in thesystem or has recently been active, then information is provided aboutthe location. This indication can refer to a geographical referencesystem or be in descriptive text, for example “in the hosiery departmentof the ladies outfitting shop ‘Damex’.” The company system can offerdirections to his wife, or alternatively give her a message or set up avoice link.

[0021] In a further development of the concept, all information betweenthe customer and the company system can be carried out by voice. For thecustomer, it is then as though he were talking to a person whorepresents the company. In the company system, the voice processing canbe carried out at several different levels, locally in the nearestcompany node, in the local central node to which the nearest companynode is connected, or in the central node or in an even higher system,depending upon what is technically the most appropriate.

[0022] What the system can offer the company in question concerningcustomer information should be obvious and is not dealt with here.

[0023] The concept of the invention can be developed further for otherareas and types of service, for example, medical care, training, factorycommunication, etc.

[0024] An arrangement and a device that has the significantcharacteristics of the invention will be described below with referenceto the attached figures in which

[0025]FIG. 1 shows schematically in outline form a communication systemarranged within a geographical area with units that carry out basestation functions or act as masters and mobile units that are to utilizethe network in question,

[0026]FIG. 2 shows schematically in outline form a different embodimentto the embodiment shown in FIG. 1, and

[0027]FIG. 3 shows principally and a table of the hop operation.

[0028] In FIG. 1 a number of company nodes are indicated by 1, 2, 3, 4and 5. The nodes are connected to a company network 6, to which a numberof synchronization nodes 7 are also connected. The company has a centralnode 8 with one or more databases 9. The company network can beconnected via the central node to an external network 10, which canconsist of a data and/or telecommunications network, for example thepublic data and/or telecommunications network. A clock synchronizationnode is also connected to the central node. The clock synchronizationnode can be influenced by the so-called GPS function 12 and obtain theGPS time via a wireless link 13 in a known way. The geographical area inquestion, that can consist of a company, hospital, factory, etc., hasbeen principally indicated by 14. Mobile units or customer nodes thatenter the geographical system 14 have been indicated by 15, 16, 17 inFIG. 1. The entering customer nodes in question can be synchronized bymeans of a synchronization node, cf. the mobile unit or customer node 17that is assumed to be synchronized as regards time with thesynchronization node 7 in FIG. 1. It is also possible to implement theclock synchronization function in other company node(s). The customernodes communicate with the company/synchronization nodes via wirelessconnections 18, 19, 20. The connection and disconnection functions canbe controlled by buttons and/or be voice-controlled in a known way.Thus, in accordance with the above, all exchange of information betweenthe customer and the company system can be carried out by means of voicecommunication, where it is for the customer as though he or she weretalking to a person who represents the company. The voice processing canbe carried out at several different levels in accordance with the above.

[0029] The embodiment shown in FIG. 2 conforms in the main with theembodiment described in connection with FIG. 1. The difference is thatFIG. 2 comprises a case where a company node 21 connected to the companynetwork 6 in turn acts as a higher-level unit in relation to a number ofcompany subsidiary nodes 22, 23, 24, and 25. In this case, the saidcompany node 21 has a local database 26. In this way, the system can,for example, serve a number of subsidiary geographical areas that arelocated within an overall geographical area. Pure data communicationand/or telecommunication can be carried out between the units in thesystem, but, for example, in this embodiment of the system, monitoringand/or controlling data can alternatively or additionally be exchangedboth as signals and voice commands for processes, carrying out commands,etc.

[0030] The invention is not limited to the embodiment described above byway of example, but can be subject to modifications within the scope ofthe following claims and concept of the invention.

1. Arrangement for a communication system which on the one handcomprises a number of company nodes which operate with a master functionand are each arranged to cover a part area in a common geographicalarea, for example within a company, in a factory, hospital, etc., and onthe other hand is arranged to allow a number of customer nodes operatingwith slave functions to be capable of being activated and deactivatedfor telecommunication and/or data communication within the commongeographical area, the system being assigned frequencies within aselected frequency band range and operating with a time gap (slot)function, which assigns the nodes time gaps (slots) within therespective part area, and a synchronizing function (for time andfrequency), for example brought about by means of a synchronizing node,one of said company nodes or a GPS function, and also comprising adatabase accessible to the respective company node, characterized inthat the company nodes are arranged to operate with coordinated timegaps (slots) and with common frequencies appearing therein which shiftsimultaneously according to the hopping system used, and in that thevarious company nodes are in this way arranged to bring about a commonidentity with regard to the respective mobile customer node and thuseliminate for the latter the requirement for handshaking in order to betaken over by the respective new company node when the customer nodepasses between part areas within the common area.
 2. An arrangementaccording to claim 1, characterized in that business transactions can becarried out via the company network.
 3. An arrangement according toclaim 1 or 2, characterized in that the company network can work withBluetooth nodes.
 4. A device in the form of a mobile data andcommunication network within a predetermined geographical area, forexample within a company, factory, hospital, etc, and working with firstfunctions, for example in the form of base station and/or masterfunctions and second functions, for example in the form of communicationfunctions and/or data functions, established by means of fixed and/ormovable mobile units and/or nodes, characterized in that two or moreunits in the first function are synchronized with each other as regardstime and frequency in order to act, from the point of view of connectionand disconnection functions, as a common first unit for second unitsthat carry out the second function, whereby handshaking procedures areavoided when the second units are moving or shifting between part areasin said predetermined geographical area.
 5. A device according to claim3, characterized in that it is based on a number of first and secondunits that operate with one or more protocols or signal specifications,for example the Bluetooth specification.
 6. A device according to claim4 or 5, characterized in that all or most of the units operating withinthe geographical area are synchronized to one and the same clock or timereference, and in the case with Bluetooth the units in question refer toone and the same Bluetooth time.
 7. A device according to claim 1, 2, 3or 4, characterized in that all or most of the units operate with asynchronized frequency hop.
 8. A device according to any one of claims4-7, characterized in that all or most of the units use the samefrequency and change frequencies simultaneously.
 9. A device accordingto any one of claims 4-7, characterized in that all or most of the unitsuse the same address functions.
 10. A device according to any one ofclaims 4-9, characterized in that within the geographical area a commonnetwork or network connections are arranged that are cable-based orwireless.
 11. A device according to claim 10, characterized in that inthe wireless version, in the planning of the nodes' Bluetooth schedule,certain or selected time slots are reserved for communication betweenadjacent company nodes.
 12. A device according to any one of claims4-10, characterized in that the nodes are arranged to exchange messages,via the common company network or connection system, with each otherand/or a central node belonging to the company with database andconnection to an additional data and/or telecommunications network, forexample the Internet, a public telephone network, etc.
 13. A deviceaccording to any one of claims 4-12, characterized in that the companynodes are preferably permanently installed and allocated geographicallocations and/or antenna layouts such that a given range pattern andoverlap pattern are obtained between the nodes, and that the time slotsare scheduled so that the available bandwidth serves an optimal numberof customer nodes in the system while retaining quality andavailability.
 14. A device according to any one of claims 4-13,characterized in that the system is constructed in principle from anumber of parallel networks that are co-ordinated with each other sothat collisions between them are essentially or completely reduced,which means that maximal space is created for other Bluetooth nodeswithin the area.
 15. A device according to any one of claims 4-14,characterized in that the customer nodes can be synchronized viasynchronization nodes or at any company node, and that thesynchronization method corresponds to the synchronization methodutilized in the Bluetooth standard.
 16. A device according to claim 15,characterized in that, in conjunction with the synchronization,information can be exchanged for further service provision in thesystem, for example, name, account number, customer profile, etc, and/orcan be updated in the central database.
 17. A device according to anyone of claims 4-16, characterized in that the central unit is connectedto a GPS node to achieve synchronization to GPS time, and that thecompany's Bluetooth time is thereby synchronized to GPS time.
 18. Adevice according to any one of claims 4-17, characterized in thatcustomer nodes that are synchronized to GPS time have the ability tosynchronize their Bluetooth time to this time, and thereby achievesynchronization to the company's nodes for their software/data withoutneeding to synchronize themselves via the synchronization node, oralternatively, after synchronization in the conventional way, are ableto be permanently synchronized via the GPS time.
 19. A device accordingto any one of claims 4-18, characterized in that the different companynodes are scheduled so that they have particular exclusive time slotswithin their area of coverage and that outside their area of coverage,the same time slots are allocated to other company nodes.
 20. A deviceaccording to claim 19, characterized in that in overlapping areas, atime slot that is allocated to a company node can be listened to by theother company nodes and that by measuring the signal strength anadjacent node is able to take over a customer node from an adjacentcompany node.
 21. A device according to claim 20, characterized in thatthe taking over is carried out when the signal strength exceeds apre-programmed threshold value or that during a transitional stage, twoor more company nodes allocate the customer node a time slot belongingto the respective company node.
 22. A device according to any one ofclaims 4-21, characterized in that the exchange of information betweenthe company system and the customer nodes is carried out completely orpartially by voice.
 23. A device for a geographical area provided with amobile internal telecommunications and/or data network in which there isa base station/master function, here called a first function, and amobile/slave function, here called a second function, characterized inthat a mobile unit that enters the area achieves synchronization to thenetwork, that the first and second functions set up query and responsefunctions, that the mobile units perform direction functions within thegeographical area, that in the event of movement of the mobile unitwithin the area, updating of this is carried out in the first function,that an interest or need function registered by the mobile unit can beprocessed in the first function, and that any payment functionassociated with the interest or need function can be implemented betweenthe first and second functions.
 24. A device according to any one ofclaims 4-22, characterized in that for closely-related mobile units, forexample belonging to different family members, groups, etc, the firstfunction distinguishes the mobile units, via which orientation functionswithin the geographical area can be initiated by means of the saidclosely-related mobile units.